The Operon Flashcards
What is an Operon?
A Operon is a set of genes and the switches that control the expression of those genes
Where is an Operon located?
Only In bacteria. It was first found in E. coli
What are the two types of Operons?
Inducible (lac) and Repressible (tryptophan)
What does RNA polymerase do in an Operon?
RNA polymerase binds to the promoter and codes the amino acids
What does tryptophan act as in an Operon?
It acts as a Corepressor
What does the corepressor do in an Operon?
It activates the repressive of the Operon
What does a activated repressor do?
It activates to the operator and prevents RNA polymerase from binding to the promoter.
What does the lac in lacOperon stand for?
Lactose
What are the three enzymes coded for in a lacOperon?
Beta-galactosidase, permease, and transacetylase.
What needs to happen in order for these three genes to be transcribed in lacOperon?
The repressor must be prevented from binding to the operator and RNA polymerase must bind to the promoter region.
What is the isomer of lactose?
Allolactose
What is an inducer in lacOperon?
Facilitates the process by binding to the active repressor and inactivating it
What is the definition of RNA polymerase,
Enzyme that transcribes a new RNA chain by linking ribonucleotides to nucleotides on a DNA template
What is the definition of the Operator?
Sequence of nucleotides near the start of an Operon to which the active repressor can attach.
What is the definition of the Promoter?
Nucleotide sequence in the DNA of a gene that is the binding site of RNA polymerase, positioning the RNA polymerase to begin to transcribe RNA at the appropriate position.
